1. Field of the Invention
The invention relates to a treatment liquid for ink jet, a treatment liquid tank for ink jet, an ink set for ink jet, an ink tank for ink jet, an ink jet recording method, and an ink jet recording apparatus.
2. Description of the Related Art
Ink jet systems for ejecting ink from an ink ejection port formed of a nozzle, a slit or a porous film have been used in many printers due to their being small-sized and inexpensive. Of these ink jet systems, a piezo ink jet system for ejecting ink by utilizing the deformation of a piezoelectric element and a thermal ink jet system for ejecting ink by utilizing the boiling phenomenon of an ink by way of thermal energy are excellent in a high resolution and a high-speed printing property.
At present, speedup and picture quality improvement on plain paper are taken as one of the important objectives of an ink jet printer. In order to attain this objectives, there has been proposed an image forming method of adhering a liquid containing a compound having a cationic group onto a recording medium and then adhering an ink containing an anion dye immediately after the liquid has permeated into the recording medium and is thus present in the medium, and has left the surface of the medium, thereby forming an image (see Japanese Patent No. 2667401, for example). In this method, in some cases in which the time required for drying of an ink is shortened, the density of an image is insufficient. In some cases in which printing is carried out with a small amount of drops, moreover, the long term ejecting property is insufficient.
For the purpose of high-speed drying, high optical density and higher image qualities, a color ink set has been proposed wherein the black ink contains water and a water-soluble solvent and has a drying time of 5 seconds or less in plain paper, and the color ink contains a coloring material, water, a water-soluble solvent, and a flocculating agent for flocculating components of the black ink and has a permeation time of 5 seconds or less in plain paper (see, for example, Japanese Patent Application Laid-Open (JP-A) No. 2001-294788). This system is excellent in optical density, bleeding and intercolor bleeding when a pigment is used as a coloring material in the color ink, but there are cases where ejecting stability is not sufficient because the flocculating agent is contained. Electrolytes or polyvalent metal salts are usually used as the flocculating agent, and their too strong effect as the flocculating agent is also problematic.
For the purpose of improving ejecting characteristics etc., an ink comprising a nitrogen-containing heterocyclic 5-membered keto-acid such as pyrrolidone carboxylic acid or its salt has been proposed (see, for example, JP-A No. 63-265681, Japanese Patent No. 2711888, and JP-A No. 2000-109735). The object of this system is to improve ejecting properties by utilizing the moisture retention effect of a salt of the nitrogen-containing heterocyclic 5-membered keto-acid. However, the ink comprising the nitrogen-containing heterocyclic 5-membered keto-acid is poor in an effect of flocculating a coloring material and cannot achieve sufficient image qualities in some cases.
As described above, optical density, bleeding, intercolor bleeding, drying time and ejecting stability cannot be simultaneously satisfied by the conventional methods.